That is a great deal on the TiVo HD. My suggestion would be to buy TiVo, then go buy a Western Digital 1TB WDEVCS (buy.com usually has them for around $100) and you will have the equivilant of a TiVo HD XL for around $300 (instead of $500).

Caution about the Guitar Center sale. Following those links led me to a Lexicon Alpha USB audio interface for $100 — only $20 more than Zzounds every-day price. The deals there may not be deals at all. Shop around before you buy.